net/mlx5: Add support to get lag physical port

Add function to get the device physical port of the lag slave.

Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/lag.c

@@ -687,6 +687,30 @@ unlock:
 }
 EXPORT_SYMBOL(mlx5_lag_get_roce_netdev);
 
+u8 mlx5_lag_get_slave_port(struct mlx5_core_dev *dev,
+			   struct net_device *slave)
+{
+	struct mlx5_lag *ldev;
+	u8 port = 0;
+
+	spin_lock(&lag_lock);
+	ldev = mlx5_lag_dev_get(dev);
+	if (!(ldev && __mlx5_lag_is_roce(ldev)))
+		goto unlock;
+
+	if (ldev->pf[MLX5_LAG_P1].netdev == slave)
+		port = MLX5_LAG_P1;
+	else
+		port = MLX5_LAG_P2;
+
+	port = ldev->v2p_map[port];
+
+unlock:
+	spin_unlock(&lag_lock);
+	return port;
+}
+EXPORT_SYMBOL(mlx5_lag_get_slave_port);
+
 bool mlx5_lag_intf_add(struct mlx5_interface *intf, struct mlx5_priv *priv)
 {
 	struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev,

include/linux/mlx5/driver.h

@@ -1074,6 +1074,8 @@ bool mlx5_lag_is_sriov(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_multipath(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_active(struct mlx5_core_dev *dev);
 struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev);
+u8 mlx5_lag_get_slave_port(struct mlx5_core_dev *dev,
+			   struct net_device *slave);
 int mlx5_lag_query_cong_counters(struct mlx5_core_dev *dev,
 				 u64 *values,
 				 int num_counters,